In light of growing international concerns regarding the spread of the Zika virus, the Fairfax County Health Department is holding open public meetings to inform residents how to best prevent the disease from spreading.
While the Zika virus has existed for more than half a century, its rapid spread across South and Central America was unprecedented. The outbreak has been going on since early 2015, and doesn’t seem to be slowing down just yet. “I’m sure it’ll spread to 2017 too,” said Shawn Kiernan, the district epidemiologist at the Fairfax County Health Department.
According to Kiernan, the disease has occurred in Northern Virginia, but of the 16 known cases in the area, none of them have spread locally. Kiernan said all of the cases are directly linked to travelers who visited a country currently affected by the Zika outbreak. However, the FCHD is actively working to detect the possibility of local transmission, meaning they’re looking for signs the disease is actively spreading from person to person via mosquitos. As of yet, this has not occurred in Virginia.
According to Josh Smith, an environmental health supervisor for Fairfax County, the mosquitoes known to carry Zika are present in the area. However, the mosquito that spread the disease the easiest, aedes aegypti, is very rare in Northern Virginia.
Another mosquito that can carry Zika, the Asian tiger mosquito, is common in the area but doesn’t spread the disease as well due to its characteristics.
“It’s just not a good vector,” said Smith, meaning that particular insect isn’t a very effective means for the virus to spread. Smith said that Asian tiger mosquitos are awkward flyers, and don’t travel far beyond where they breed, so if you see them flying around, “they’re most likely from your own backyard.”
Additionally, Smith said these insects aren’t picky, so they spend most of their time feeding on hosts that aren’t necessarily human.
The best way to prevent the spread of the Zika virus and other mosquito-borne illnesses is to interrupt their life cycle, according to the FCHD. “But we can’t go everywhere,” Smith said, referring to the fact that most places where these insects breed are containers on private property.
The FCHD encourages homeowners to walk their property at least once a week and dump out any containers that hold standing water, including things such as empty plant pots, uncovered and drained hot tubs, old tires, and any other place that can collect average amounts of standing water (but excluding swimming pools, as they’re too large for the insect). Additionally, the mosquitos that are known to carry the Zika virus do not breed in still water ponds, pooling lakes, stormwater management areas or drainage ditches, so Smith considers those areas to be of least concern when it comes to combatting the Zika virus.
If a container can’t be dumped, the FCHD recommends treating the water with a mosquito larvicide, available at local home improvement stores. The larvicide specifically targets mosquito larvae, and will not harm other animals.
“Source reduction is the most important effort,” said Smith. According to the FCHD, active homeowners are often the best line of defense.